1. Field of the Invention
This invention relates to trace mineral supplements which are suitable for addition to vitamin A-containing supplements.
2. Description of the Prior Art
It is common practice to add various minerals to poultry and livestock feeds. For example, many such feeds have mineral supplements added to them which are mixtures of materials such as limestone, steamed bone meal, dicalcium phosphate and salt. Such mineral materials are added to poultry and livestock feeds in amounts which are comparatively large as compared to the amounts of so-called trace minerals which are added to such feeds. The trace minerals most frequently added to feeds are compounds of manganese, copper, iron, cobalt, iodine, zinc and selenium. Supplementary amounts of these trace minerals are usually considered necessary for ruminants and all of them, with the exception of cobalt, are considered necessary additions for swine and poultry feeds.
It is also common practice to supplement poultry and livestock feeds with vitamin A. In many cases feed manufacturers purchase supplements for addition to their feeds which contain both vitamin A and minerals, including trace minerals. These supplements are quite often referred to as premixes, although they may contain other ingredients such as limestone and antibiotics.
Most minerals, particularly trace minerals, have a very detrimental effect on vitamin A. This is especially so in vitamin and mineral supplements because the concentration of minerals is considerably higher than in the finished feed product. The problem is intensified where the supplement or feed which contains both the vitamin and trace minerals is exposed to large amounts of moisture. Degradation of the vitamin also varies depending upon the nature of the carrier for the vitamin. Attempts have been made in the past to provide trace minerals in a form in which they will not detrimentally affect the stability of the vitamin. For example, according to Canadian Pat. No. 553,210--Hochberg--Feb. 11, 1958, trace mineral supplements have been prepared by admixing trace minerals with a normally solid wax-like material and a vegetable meal.